High-fidelity loudspeaker system



March 26, 1963 J. E. wHlTcAs 3,082,839

HIGH-FIDELITY LoUDsPEAKER SYSTEM Filed March 27, 1959 2 sheets-sheet 1 lll I lMarch 26, 1963 2 Sheets-Sheet 2 Filed March 27, 1959 United States Patent O 3,082,839 HIGH-FIDELITY LOUDSPEKER SYSTEM `loseph E. Whitcas, South Merchantville, NJ. (416 Yale Ave., Cherry Hill, NJ.)

Filed Mar. 27, 1959, Ser. No. 802,499 1? Claims. (Cl. 181-31) This invention relates to loudspeaker systems of the high-fidelity type and has for an object the provision of a relatively small loudspeaker cabinet which is tubular in shape having mounted in the side wall thereof a relatively long, narrow loudspeaker so as to provide accurate and natural sound reproduction from the system over a wide frequency range.

It is another object of the invention to provide an arrangement for increasing the bass response of the loudspeaker system.

It is a further object of the invention to provide a relatively small loudspeaker cabinet which is pleasing in appearance, substantially free'from distortion over an extended frequency range and is economical to manufacture.

It is a further object of the invention to provide a highfidelity speaker cabinet constructed so that it is suitable as the Vbase of a table lamp or the like and is particularly adapted for use in pairs in stereophonic sound systems,

In accordance with one aspect of the invention the loudspeaker cabinet includes an iinner tubular member having a length substantially greater than its maximum inside diameter and an outer tubular member surrounding tne inner tubular member and spaced therefrom to provide a chamber between the adjacent walls of the tubular members. Mounted in the wall of the inner tubular member is a loudspeaker having a length substantially greater than the inside diameter of the inner tubular member and having a width substantially less than its length. The loudspeaker is mounted in the wall of the inner tubular `rnen'rber with the long dimension of the speaker extendvacoustic enclosure for the speakerrand the outer tubular `member is provided with aperture means inthe wall thereof opposite the speaker. The aperture means in the Wall of the outer tubular member preferably comprises a pl-urality of small openings in the area of the wall opposite the speaker and sound transparent material extends around the outer surface of the outer tubular member and over the plurality of small openings.

In a further aspect of the invention the loudspeaker, which is adapted to be mounted in the loud speaker cabinet, comprises a cone which is supported on a metal frame. The metal frame is provided with a plurality of apertures at the rear of the cone and a baffle plate is secured to the frame at the opposite side thereof from the cone, the baille plate having an area sufficient to overlap the apertures in the frame to provide increase in the bass 'response of the speaker.

F or further objects and advantages thereof and for a more detailed understanding of the invention, reference lis to be had to the following description taken in con- Ijunction with the accompanying drawings in which:

FIG. l is a perspective View of an embodiment of the invention as applied to the base of a table lamp;

FIG. 2 is an enlarged sectional view of the embodiment shown in FIG. l; v

FIG. 3 is a horizontal sectional view taken along the lines 3--3 in FIG. 2;

FIG. 4 is an enlarged rear elevational View of the embodirnent shown in FIG. l;

FIG. 5 is a modification of the invention; and

FIG. 6 is an enlarged sectional view taken along the lines 6 6 in FIG. 5.

Referring to FIG. 1, there is shown a table lamp 10 the base of whichcomprises a high-fidelity loudspeaker cabinet 11 embodying the present invention. Projecting from the upper or top end of the cabinet or -base 11 is an electrical fixture 12 which is adapted to support a suitable shade 13. t

Referring to FIG. 2 the cabinet 11 includes an inner tubular member 14 which is cylindrical in shape and has an opening 14a, FIGS. 2 and 3, in the curved wall thereof adapted to receive a loudspeaker 15. The tubular member 14 has a length substantially greater than its maximum inner diameter. The speaker opening 14a is of substantial length, FlG. 2, approaching the length of the tubular rnember 14 and has a width, FIG. 3, substantially less than the maximum inner diameter of the tubular member 14. In the preferred .form of the invention the width of the speaker opening is in the order of about one to three inches wide and has a length in the order of about five to seven times the width. It has been found that for best results, particularly in regard to tone quality and bass response, the width of the speaker opening should be su=b stantially less than the Width of the speaker enclosure.

The speaker opening is adapted to receive a long, narrow speaker 15 of corresponding size such for example as a speaker of the type disclosed in Patent 2,820,527. It is to be understood, however, that the present invention is not limited to a speaker such as disclosed in the aforesaid patent and that other long, narrow speakers may be utilized. iFor example, in one cabinet constructed in accordance with the present invention the inner tubular member 14 had a length of about twelve inches, an inside diameter of about 4% inches, an outside diameter of about 5%, inches and was constructed from a heavy paper tube. The speaker opening in the side wall of the tube was about two inches Wide and about ten inches long, and the speaker mounted in the opening was of As may be seen in FIG. 2, the speaker 15 is provided with a metal frame 19 having apertures 19a therein. The frame 19 is adapted to support a cone 21. The frame 19 includes a rear section 19h ywhich is adapted to extend around a magnet 22 at the rear of the speaker 15. As may be seen in FiGS. 2 and 3, the speaker 15 is adapted to be mounted from the rear as by a pair of screws *24 which are adapted to extend through openings in the side wall of the inner tubular member 14 and into tapped holes in the rear of frame section 1917. The interior of the tubular member 414 is separated into two acoustic chambers 11a, 11b by ta partition 26 which is disposed substantially midway between the ends 17 and 18 of the 3 cabinet and parallel thereto. The partition 26 has a cutout portion 26a, FIG. 3, which is adapted to extend around the rear of the speaker 15. The interior of the tube 14 is lined with sound insulating or `clamping material 27, such for example as soft paper, foam rubber, Fiberglas or other similar sound damping material.

It has been found that the range of response ot the speaker 15 may fbe extended by providing a rear baille plate 28 which is made from a hard, sti and substantially homogeneous material such for example as metal `or hard plastic. It will be noted that the baffle plate 28 extends into 'both chambers or sections 11a, 11b of the cabinet 11 on either side of the separator 26 and overlaps the openings 19a at the rear of the speaker frame 19. While the baffle plate 28 may be mounted on the separator 26, it is preferably secured to the rear frame section 19b for ease in installation. The baille plate 28 may be secured to the frame member 19b in any suitable manner, such for example as by a suitable adhesive, such as an epoxy resin. In one installation, with a speaker approximately two inches wide by ten inches long, the baille plate 28 was approximately two inches wide, about one-eighth inch thick and had a length between about yfour and eight inches. The ybass response of a loudspeaker cabinet assembly 11 with a bacle plate 28 of the foregoing type was substantially improved over the response without such baille plate and in general the length of the plate 28 varies inversely with the weight or strength of the speaker magnet '22 for such improved bass response.

As may be seen in FIGS. 2 and 3, the inner tubular member 14 is provided with an outer tubular member -3-1 which is spaced therefrom to form an outer chamber 32 therebetween. The 4tubular members 14 and 431 are rspaced from each other by a pair of spacer rings 33 and 34 disposed at the opposite ends of the cabinet 11 and a central spacer member 35. The spacer members 33 and 34 may be in the form of complete rings, whereas the middle spacer member 35 has `a portion cut therefrom, as may be seen in FIG. 3, so as not to interfere with the front of the speaker 15. To provide longitudinal support for the outer tubular member 31, there is provided a vertical support in the form of a rib 37 extending lengthwise of the cabinet 11. While the outer tubular member "31 may be lformed from tubular stock, it is preferably `formed from non-foraminous sheet material, such for example as heavy paper, fiber or asbestos with the two end thereof being secured to the vertical support or ri-b 37 by suitable means, such for example as staples. 'I'he upper and lower edges of the tubular member 31 are adapted to be secured to the respective ring members v33 and 34 by suitable means, such as staples.

The outer tubular member 31 is provided with aperture means directly opposite the front of the speaker 15. The aperture means in a preferred form of the invention includes a plurality of small openings or holes 40. In a cabine-t constructed in accordance with the invention, the outer tube 31 was provided with approximately ninety holes opposite the front of the speaker. The holes were approximately three-eighths inch in diameter and were'staggered on three-eighths inch centers. It was found that by providing the outer chamber 32 around the inner chambers 11a, 11b in the tubular member l14, and with aperture means of the foregoing type, the bass response of the cabinet 11 was materially increased.

To provide an attractive appearance 'for the cabinet 11, the outer surface of the outer tubular member 31 is covered with suitable sound transparent material such for example as grill cloth 42. The grill cloth 42 extends over the openings 40, thus concealing them from view but without Iblocking the sound from the speaker 1S. Since there are wall areas of tubular member 3-1 =between the openings 40, some of the sound waves from the speaker 15 will be directed through the openings 40 while other portions of thc sound waves will be reilected back into the 4outer chamber 32 surrounding the inner tubular member 14. As may be seen in FIG. 4, the opposite ends of the grill cloth 42 are adapted to be secured to the vertical rib 37 by suitable means, such for example as staples 43. The seam in the grill cloth and the `staples 43 are then adapted to be covered by a strip of trim material l45, such for example as a strip of Mylar or other suitable trim strip. The top and bottom edges of the grill cloth 42 are adapted to be secured to the outer surface of the outer tubular member 31 and the ends thereof adjacent the spacer rings 33 and 34, FIG. 2, by suitable means, such for example as staples, adhesive or the like. These edges are then adapted to `be covered by suitable trim strips 46 and 47, FIG. 4, such for example as strips of Mylar or other suitable material.

To provide additional weight for the cabinet or base 11, the opposite ends thereof are provided with plate members 48 and 49. The plate members 48 and 49 are adapted to cover the corresponding end members 17 and 18 and the corresponding end rings 33 and 34, as Well as the ends of the tubular members I14 and 31. Since all of theseportions are obscured from view by the end members 48 and 49, the latter members are the only ones that need to be provided with a decorative nish. The end members 48 and 49 may be made from various materials, such for example as walnut, mahogany, birch, oak or other decorative wood, or they may be made from other suitable materials, such as marble, plastic, metal or the like.

As may be seen in FIG. 2, when the cabinet 11 is employed as a lamp base the end plate 48 and the end member 17 have apertures or passages 48a and 17a therein through which a pipe section 50 from the electrical fixture 12 is adap-ted to extend. A nishing tube 51 extends over the pipe section 50 and is positioned between a support member 52 of the electrical fixture and the upper surface of end member 48. The lower `end of the pipe section 58 is' threaded and is adapted to receive a nut member 54 whichV is adapted to cooperate with the iinishing sleeve 51 and clamp the end means including members 17 and 48 therebetween, as shown in FIG. 2. The lower end members 18 and 49 likewise are provided with passages :18a and 49a extending therethrough. The electrical cord 55 for the lamp is adapted to extend through the passages 49a and 18a in the end members 1S and 49 and through the pipe section 50 to the electrical fixture 12, while the conductor 56 for electrical connection to speaker 15 also extends through the passages 18a and 49a, as shown in FIG. 2. The bottom end member 49 has a shape adequate to support the complete table lamp 10 in a vertical position as shown in FIG. 1.

Referring to FIGS. 5 and `6, there is shown a modification 11 of the invention. `In this' modification, to further increase the bass response of the speaker cabinet 11', the inner tubular member 14 is provided with a plurality of slots 1412, 14e disposed directly opposite the rear of the speaker 15, FIG. 6. As may be seen in FIG. 5, the openings of slots 1411 are `disposed above the separator member 26 and on opposite sides of the Vertical rib 37. The slots 14C are disposed on opposite `sides of the rib 37 and below the middle separator plate 26. As may be seen in FIG. 6, air may pass' from chambers lla, lilb within the inner tubular member 14 at the rear of the speaker 15, out throughV the openings 14b and 14e, around through the ring-like outer `chamber 32 between the adjacent walls of the inner tubular member .14 and `the outer tubular member V31 and out through the openings or portsr40 in the outer tubular member 31 which are directly opposite the front of the speaker 15. v

From the foregoing description -it will be seen that the speaker cabinet 11' is similar to the speaker tabi-V net 11, shown in FIG. l, and that the speaker cabinet 11 likewise is adapted to support an electrical fixture similar to the lamp fixture 12 shown in FIG. 2. The pipe section 50 may be of Isuitable length to extend completely through the interior of the cabinet 11' and into the end members 18 and 49, thus providing conduit means for protecting the electrical cord 55 contained therein. The lower sur-face of the bottom or end members 49 may be provided with a pad 58 of suitable material such for example as felt or cork, such as is usually found on the bottom of a lamp base.

In the modification shown in FIGS. 5 and 6, the speaker 15 has been mounted to the inner tubular member 14 by screws 60 extending through the front of the frame l19 of the speaker. In both embodiments of the invention the speaker 15 when mounted in the tubular member 14 is sealed around the edges of the frame 19 to the tubular member 14 by suitable material 61. One material which has been found to be suitable is plastic modeling clay. The clay 61, FIG. 2, is adapted to extend completely aroundA the periphery of the front portion `of the frame 19 o-f the loudspeaker 15 and form an air-tight seal with respect to the outer surface of tubular member 14.

In one speaker cabinet embodying the modification shown in FIGS. 5 'and 6, the lengths of the slots 14b and 14e` were approximately two and one-half inches each and they had a width of approximately one-half inch. The spacing between the outer wall of tubular member 14 and the inner wall of the tubular member 31 Was in the order of about one-half inch and the outs-ide diameter of tubular member 14 was about liveand-one-quarter inches with the overall length being approximately twelve inches.

Loudspeaker cabinets built in accordance with the present invention, while relatively small in size, nevertheless have acoustical properties which ordinarily are found only in cabinets of substantially larger size. Loudspeaker cabinets constructed in accordance with the present invention not `only are economical to construct, but are also pleasing in appearance. Because of their pleasing appearance, relatively small size and extended frequency range reproduction, such loudspeaker cabinets are particularly well-suited as bases for lamps or the like and when employed -in pairs provide a particularly desir able arrangement for stereo sound systems.

It shall be understood that the invention is not limited to the preferred embodiments specifically shown and described, but comprehends other modifications within` the scope of the appended claims.

What is claimed is:

l. A loudspeaker cabinet comprising a curvedsolid wall tubular member having a length substantially greater than its maximum inner diameter, a pair of end members closing the opposite ends of said tubular member, a speaker opening disposed in the Wall of said tubular member, said speaker opening having a length substan tially co-extensive with the length of said tubular member and a width substantially less than said maximum inner ldiameter of said tubular member, and an outer solid wall tube surrounding said irst-named tubular member and spaced therefrom to form an air chamber therebetween, said outer tube having an opening therein directly opposite the speaker opening in said first-named tubular member.

2. A loudspeaker cabinet according to claim 1 wherein said outer tube is provided with a plurality of small openings directly opposite said speaker opening in said firstnamed tubular member, and a sound transparent material extending around said outer tube and continuing over said plurality of small openings.

3.` A loudspeaker cabinet according to claim 1 wherein said tubular member includes an inside divider member which separates the interior of said tubular member into two compartments and each of said compartments is lined with acoustical insulation material.

4. A loudspeaker cabinet assembly comprising an inner tubular member of non-foraminous material having a length substantially greater than its maximum inside diameter, an outer tubular member of non-foraminous material completely surrounding said inner tubular member and spaced therefrom to provide a chamber between the adjacent walls of said tubular members, a speaker, said speaker having a length substantially greater than said inside diameter of said inner tubular member, said speaker havinga width substantially less than its length, said speaker being mounted in the wall of said inner tubular member with the long dimenison of said speaker extending axially of said inner tubular member, and means sealing the opposite ends of said tubular members, said outer tubular member having aperture means in the wallthereof opposite said speaker.l

5. A loudspeaker cabinet assembly according to claim 4 wherein said aperture means in said wall of said outer tubular member comprises a plurality of small openings in the area of said wall opposite said speaker.

6. A loudspeaker cabinet assembly according to claim 4 including sound transparent material extending around the outer surface of said outer tubular member and over said aperture means.

7. A loudspeaker cabinet assembly according to claim 4 wherein said outer tubular member is formed from relatively stiff sheet material, a support extending lengthwise of said tubular members between said adjacent walls thereof, and means securing the opposite ends of the said sheet material to said support to form said sheet material into said outer tubular member.

8. A loudspeaker cabinet assembly according to claim 4 wherein said inner tubular member is provided with additional aperture means in the wall thereof at a location spaced from said speaker t0 provide communication between the interior of said inner tubular member and said chamber formed between said adjacent walls of said tubular members.

9. A loudspeaker cabinet assembly according to claim 4 including a baille plate mounted within said inner tubular member at a location directly behind said speaker and spaced from the interior surface of said inner tubular member.

10. lA loudspeaker cabinet assembly comprising a tubular member of non-foraminous material having a lengthv substantially greater than its maximum inner diameter, a pair of end members closing the opposite ends of said tubular member, a speaker opening -in the wall of said tubular member, a speaker ldisposed in said speaker opening, said speaker having a length approaching the length of said tubular member and a width substantially less than said maximum inner diameter of said tubular member, and baille means mounted within said tubular mem,

ber directly behind said speaker and spaced from the inner surfaces of all of the walls of said tubular member, said baille means comprising a plate having an area less than the area of said speaker opening and extending transversely of said speaker opening.

ll. A loudspeaker cabinet assembly according to claim 10 wherein the interior of said tubular member' is separated into a pair of compartments transversely of the axis of said tubular member and said baille means extends into aosasse opening, sealing means extending around the periphery of said speaker and said speaker opening to seal said speaker to said front wall of said tubular member, and baille means mounted within said tubular member directly behind said speaker, said baille means comprising a plate having an area less than the area of said speaker opening and substantially parallel to said opening, said plate being disposed centrally of said speaker and the length and width of the plate being less than the respective length and width of Vthe speaker opening so that all of the edges of the plate are'spaced from the inner surfaces of the Wallsof said tubular member.

13. A loudspeaker cabinet assembly according to claim 12 wherein said speaker comprises a cone, a metal frame supporting said cone, said metal frame having apertures therein at the rear of said icone, and said plate of said.

baille means is secured to said frame at the opposite side thereof from said cone and having an area sucient to overlap said apertures in said frame.

References Cited in the file of this patent UNITED STATES PATENTS Friedline Jluly 10, Semple fOct. 14, Nicolson Sept. 10, Bobb Nov. 3, Volf Mar. 13, Petel July 3, Sewell Sept. 17, Bobb et al. Jan. 21, Perlman June 17, Lopez-Henrquez Nov. 4, Wylczik May 26, Holland Mar. 1, Pinski Mar. k7,

FOREIGN PATENTS Germany Apr. 17, France Mar. 18, 

1. A LOUDSPEAKER CABINET COMPRISING A CURVED SOLID WALL TUBULAR MEMBER HAVING A LENGTH SUBSTANTIALLY GREATER THAN ITS MAXIMUM INNER DIAMETER, A PAIR OF END MEMBERS CLOSING THE OPPOSITE ENDS OF SAID TUBULAR MEMBER, A SPEAKER OPENING DISPOSED IN THE WALL OF SAID TUBULAR MEMBER, SAID SPEAKER OPENING HAVING A LENGTH SUBSTANTIALLY CO-EXTENSIVE WITH THE LENGTH OF SAID TUBULAR MEMBER AND A WIDTH SUBSTANTIALLY LESS THAN SAID MAXIMUM INNER DIAMETER OF SAID TUBULAR MEMBER, AND AN OUTER SOLID WALL TUBE SURROUNDING SAID FIRST-NAMED TUBULAR MEMBER AND SPACED THEREFROM TO FORM AN AIR CHAMBER THEREBETWEEN, SAID OUTER TUBE HAVING AN OPENING THEREIN DIRECTLY OPPOSITE THE SPEAKER OPENING IN SAID FIRST-NAMED TUBULAR MEMBER. 